docs: def get_affected_box(self, src):
          """
          Get the enlarged bounding box of a source.
  
          :param src: a source object
          :returns: a bounding box (min_lon, min_lat, max_lon, max_lat)
          """
          mag = src.get_min_max_mag()[1]
          maxdist = self(src.tectonic_region_type, mag)
          bbox = get_bounding_box(src, maxdist)
          return (fix_lon(bbox[0]), bbox[1], fix_lon(bbox[2]), bbox[3])